At 1318 ZT on 10 September, in DR position LAT 24° 05.8'N, LONG 058° 08.3'E, you observe an amplitude of the Moon. The upper limb of the Moon is on the visible horizon and bears 254° psc. Variation is 2°W. What is the deviation?

Correct Answer: Option C — 4.0°W

Derive true azimuth via standard celestial amplitude calculations for the Moon's upper limb on the visible horizon. Combine observed psc bearing, calculated true bearing, and local variation following standard Bowditch navigational procedures to determine the residual deviation.